Liu Chenyang, Li Shuang, Wu Zelin, Yang Jianlong, Qin Jibo, Dou Yibo, Han Jingbin, Zhang Wenjing, Tang Junwang
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
Industrial Catalysis Center, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China.
ACS Appl Mater Interfaces. 2025 May 14;17(19):28188-28198. doi: 10.1021/acsami.5c02560. Epub 2025 May 3.
Chemical upcycling of plastic wastes into valuable chemical feedstocks and simultaneous mitigation of environmental deterioration are fascinating but remain extremely challenging. Herein, we report microwave-assisted valorization of plastic wastes into carbon nanotubes (CNTs) and hydrogen (H) over heterojunction-structured mixed metal oxides. Specifically, the CoNiFe-based layered triple oxides (LTO) arrayed on Ni-foam (CoNiFe-LTO@foam) were constructed. The special heterojunction of the LTO endows high dielectric loss, facilitating efficient conversion of absorbed microwave energy into thermal energy. Most importantly, the synergistic effect of the multiple transition metal sites boosts the cleavage of carbon chains and dehydrogenation, thereby accelerating the reaction kinetics. As a result, the CoNiFe-LTO@foam achieves an H selectivity of ∼95 vol % with the yield of ∼69 for upcycling polyethylene in 25 cycles of measurement. Simultaneously, the CNTs attain a yield of ∼35%, which can be used for aqueous chloride-ion batteries. Additionally, the CoNiFe-LTO@foam enables facile recovery of CNTs and prevents the loss of catalytic sites, facilitating upcycling of various real-world plastic wastes. Our work thus highlights the innovations of an advanced catalytic system for forming a closed loop of plastic C/H and achieving the ultimate goal of a carbon-neutral society.
